The present invention relates to a rotary electric machine, such as an electric power generator and an electric motor, fixing a stator core therein.
In rotary electric machines, a stator core fixed to a housing turns by a rotating force generated by a rotor. Therefore, it is necessary to tightly fix the stator core not to turn in the housing as proposed in JP-A-9-172747 and JP-U-5-15647.
JP-A-9-172747 uses bolts having a tapered engaging portion. The bolts are threaded into grooves provided on an outer periphery of the stator core in an axial direction. The tapered engaging portion of the bolt is fit in the groove, and an axial force generated by fastening the bolt is decreased. Therefore, the stator core is not tightly fixed in an axial direction. Moreover, electric power is decreased due to magnetic resistance caused by the grooves of the stator core.
JP-U-5-15647 uses a taper pin. High quality is required to the taper pin, and it is difficult to fit the taper pin accurately. When the taper pin is fit in grooves provided on an outer periphery of a stator core, the stator core is likely to be remarkably deformed so that the electric power is decreased or magnetic noise occurs. Further, once the taper pin is fit, it is difficult to remove the taper pin and repair is difficult.
It is also proposed to fix a stator core to a housing by threading bolts into bolt holes formed in the housing in the axial direction.